The present invention relates to a method of manufacturing a semiconductor device, and, more specifically, to a technique effectively applied to an electrode constituting a capacitor.
For example, a DRAM (Dynamic Random Access Memory) has a memory cell selecting MISFET and a data storage capacitor connected to the MISFET in series. This data storage capacitor is formed by sequentially depositing, for example, silicon to be a lower electrode, tantalum oxide to be a capacitor dielectric film, and silicon to be an upper electrode.
For example, Japanese Patent Laid-open No. 5-55464 discloses a method of forming a tantalum tungsten film containing tantalum on a polycrystalline silicon film (lower electrode), selectively oxidizing this film in mixed gas of hydrogen and water vapor, and forming a charge storage dielectric film by a tantalum oxide film.
However, in the case where silicon is used as a material of the lower electrode, a silicon oxynitride layer is formed on an interface between silicon and tantalum oxide at the time of a heat treatment (in an oxygen atmosphere, at 700xc2x0 C.) for the crystallization of tantalum oxide formed on the lower electrode and for the improvement of the film quality thereof. Thus, it has been difficult to make the lower electrode have a high dielectric constant.
The inventors of this invention have been engaged in the research and development of DRAM and examined various configurations and manufacturing methods of the above-mentioned data storage capacitor.
With the downsizing of the semiconductor integrated circuit device, an area used to form the data storage capacitor also tends to be reduced, and thereby it has become difficult to obtain a desired capacitance thereof. Therefore, the studies for electrode materials and capacitor dielectric materials have been demanded to obtain the data storage capacitor with a large capacitance and a small area.
Thus, the inventors have used an Ru film as a lower electrode of the data storage capacitor and made various studies for the manufacturing method thereof. This is because a platinum group metal like Ru forms no low-dielectric-constant film such as a silicon oxynitride film even by the heat treatment performed after the data storage capacitor is formed, and can be formed thinly owing to metal, and thereby is considered to be suitable to increase the capacitance thereof.
As a method of forming the Ru film, for example, a CVD method using a tetrahydrofuran solution of ethylcyclopentadienylruthenium (Ru(C2H5C5H4)2) and O2 (oxygen) as materials is available.
However, in the film forming method using the reaction between an organic compound (ethylcyclopentadienylruthenium) like this and oxygen, the organic compound itself and a compound of the organic compound and oxygen are left in the Ru film, thereby resulting in deterioration of the quality of the Ru film.
An object of the present invention is to provide a technique capable of improving a film quality of a metal film formed by the CVD method, for example, an Ru film and the like constituting a lower electrode of a data storage capacitor.
Another object of the present invention is to improve the characteristic of a semiconductor integrated circuit device by forming a good metal film therein.
The above and other objects and novel characteristics of the present invention will be apparent from the description of this specification and the accompanying drawings.
The advantages achieved by the typical ones of the inventions disclosed in this application will be briefly described as follows.
1. A method of manufacturing a semiconductor device according to the present invention is one in which a platinum group metal is formed on a semiconductor substrate by a reaction using a one-valence or two-valence platinum group compound as a material and H2O as a catalyst.
2. A method of manufacturing a semiconductor device according to the present invention comprises the steps of: forming a first conductor on a semiconductor substrate; forming a second conductor on said first conductor; and forming a third conductor on said second conductor, wherein the third conductor made of a platinum group metal is formed by a reaction using a one-valence or two-valence platinum group compound as a material and H2O as a catalyst.
3. A method of manufacturing a semiconductor device according to the present invention is one in which a platinum group metal is formed on a semiconductor substrate by a disproportionate reaction using a platinum group compound as a material and H2O as a catalyst.